My question is this... I have installed a G62 into my 33 % Extra 230 and need to get some advise on engine spacing. With the motor installed to the firewall and the cowl temporarily mounted to the plane I come up about 3/8 to 1/2 inch short of the prop hub I guess you would call it. I need to get the motor out another 1/2 " and to do this I would think that I would have 3 or 4 options.

I could move the cowl back the distance that I needed, but I really didn't want it back that far if I did not have to.
I could add a 1/2" block behind the motor mount and the firewall.
I could add an aluminum spacer behind the prop hub between the flywheel (?) Don't know if that would cause a balance problem ?
I could cut the cowl down to shorten the length by 1/2" inch.

Does anyone have any in put on this that they would like to share ?

Thanks

Put 4 spacers between the firewall and the back of the motor. You can make these spacers from 3/4 inch dowel, drilled thru for the bolt. Of course your bolts will have to be long enough to go completely thru the lugs on the motor case all the way to the back of the firewall. This is pretty typical for gassers on airplanes. You can even buy aluminum spacers for just such a purpose.

Definitely move the engine out. If you shorten the cowl, you may have to add extra weight up front to balance the airplane.

To cover 1/2", you can use 3/4" hardwood dowel as suggested by DMcQuinn, or build the spacers from 1/4" aircraft-quality ply wood.

--qc